Probe systems are used, for example, for determining the positions of workpieces which are clamped into material-working machines such as milling machines, for example. These probe systems frequently have a stationary transceiver unit, which is mounted on a permanently installed element of the material-working machine, and a part that is movable or mobile with respect to the latter, which is frequently referred to as a probe head. The probe head is for the most part mounted on a movable element of the material-working machine, for example, on a milling spindle. In this context, the probe head includes a feeler that is deflectable out of a rest position or a deflectable probe element, which produces a switching signal in response to a deflection out of its rest position. The rest position of the probe element is understood to be a position where the probe element does not have any contact with a workpiece. In response to contact of the probe element with the workpiece, the probe element is deflected out of its rest position.
In so-called wireless probe systems, the corresponding switching signal is transmitted from the probe head as an electromagnetic signal, e.g., as an infrared signal, to the stationary transceiver unit. In the transceiver unit, the output signals of the probe system are analyzed in order to determine the occurrence of switching signals (i.e., a deflection of the probe element). Thus, frequently there is no cable connection between the probe head and the stationary transceiver unit.
For its energy supply, such a probe head often has a direct-current source in the form of one or more batteries. There is believed to be a constant desire to increase the availability of such probe systems, which is why there is an effort to maximize the service life of the direct-current sources.
European Published Patent Application No. 1 179 173, for example, describes a battery-operated probe head, which may prolong the service life of the batteries by various measures, which may ultimately improve the availability of the respective probe system because of less frequent standstill times due to exhausted batteries.
European Published Patent Application No. 0 217 808 and U.S. Pat. No. 5,564,872 provide for equipping a probe head with a turbine and a generator in order to produce electrical energy for operating the probe head by applying compressed air. Conventional systems are used as generators. Such devices require a comparatively large amount of space.